a.) Objective of this Research: The purpose of this study is to investigate the safety, efficacy and dose response of quinapril, an ACE inhibitor, in the treatment of children ages 5 to 16 with hypertension. b.) Study Design: This is a double-blind, placebo-controlled, parallel group, randomized design. A 10 to 14 day, single-blind, placebo lead-in phase followed by stratification, based on weight into 1 of 2 strata. Each stratum will include 4 treatment groups, a 2-week blinded treatment phase and a 6-week blinded extension. The study medication will be dispensed in pill form.